ReQuest bad panel or what?

[Brandon Hartwick]

You should have 3 wires, 2 wires go to the front and back stator and the 3rd connects to the mylar to energize it.

Losing one of the stators while playing music could lead to some weird results, not sure if it would sound similar to your issues or not. But for everyone saying "oh they're just old", I don't buy it as an old panel doesn't come back to life for an hour and then stop working again.

 

[Shaftish]

I don't buy it either. They might be old but this is something else.
I have 4 wires, red, 2xblue, black.

 

[Shaftish]

Front stator, 2xblue.
Mylar, red.
Back, black.

 

[Brandon Hartwick]

Front stator, 2xblue.
Mylar, red.
Back, black.

Ok they might be energising the panel from both sides or something, the operation remains the same.

Hard to say what's causing the issue, mechanical interference somewhere maybe, crappy connection somewhere? If you figure it out let us know, I'm curious.

 

[Shaftish]

I will try to clean them again tomorrow.
Maybe I'll get lucky

 

[Shaftish]

I did.
It was working just fine untill this interference showed up.

Anyone who can translate the wierd noice, is it dirt related?

 

[Robert D]

I did.
It was working just fine untill this interference showed up.

Anyone who can translate the wierd noice, is it dirt related?

Sounds like a Geiger counter. Weird.

 

[Brandon Hartwick]

I did.
It was working just fine untill this interference showed up.

Anyone who can translate the wierd noice, is it dirt related?

Wash it again lmao, 3rd times the charm

In all seriousness I don't know what's up, if you're really up for some troubleshooting I'd take all your findings and post them up on Diyaudio.com, there's people on there that actually build there own ELS's and will probably have more ideas.

 

[Shaftish]

Good idea, that played almost an hour before it went silent and about 30 minutes before the interference accorded.
I'll make an account on DIY

But I will wash it tomorrow, and dry it with compressed air.

 

[Brandon Hartwick]

Good idea, that played almost an hour before it went silent and about 30 minutes before the interference accorded.
I'll make an account on DIY

But I will wash it tomorrow, and dry it with compressed air.

I was joking about washing it again haha, be careful if you're using an air compressor because the mylar is obviously super thin.

Back when I washed my panels I sprayed them down with simple green chemical free cleaner and let it sit for a minute. I washed them off front and back in the shower and then with a spray bottle with distilled water so I didn't leave any deposits. I used a vacuum to try them then I let them air dry for a few days to let the foam dry out.

 

[Jazzman53]

If the panel itself were arcing that bad it would likely have burned thru the stator coating, shorted catastrophically, and tripped the protection on your amp by now... I'm thinking you have something going on in the bias supply (cold solder joint arcing, leaking capacitor, or a diode starting to conduct both ways) or a corroded connection where the bias supply wire connects to the diaphragm.

Try swapping the panels. If the problem doesn't follow the panel, then it's probably the bias supply.

 

[Shaftish]

If the panel itself were arcing that bad it would likely have burned thru the stator coating, shorted catastrophically, and tripped the protection on your amp by now... I'm thinking you have something going on in the bias supply (cold solder joint arcing, leaking capacitor, or a diode starting to conduct both ways) or a corroded connection where the bias supply wire connects to the diaphragm.

Try swapping the panels. If the problem doesn't follow the panel, then it's probably the bias supply.

The problem follows the panel.

 

[Jazzman53]

I should have read thru the entire thread before commenting earlier.
OK; the problem is in the panel and there is obviously arcing going on.

The symptoms you describe (sometimes plays and sometimes doesn't) leads me to believe the arcing fault is occurring at the bias supply wire-to-diaphragm connection. It could be stator-to-diaphragm or stator-to-stator arcing but I think that's less likely.

Arcing at the bias supply connection would sound like it's coming from the entire panel rather than the local connection area because it affects the charge across the entire diaphragm.

Some ML's just have a wire taped in place against the diaphragm (piss poor if you ask me) and some use a copper foil strip contacting the diaphragm (much better).

If you have the wire-only contact; you could apply some conductive paint of the kind used to repair automobile rear window de-icing grids (available at auto parts stores), or you could solder a copper foil strip to the wire to make a larger contact patch to the diaphragm.

Hope this helps

 

[Shaftish]

I should have read thru the entire thread before commenting earlier.
OK; the problem is in the panel and there is obviously arcing going on.

The symptoms you describe (sometimes plays and sometimes doesn't) leads me to believe the arcing fault is occurring at the bias supply wire-to-diaphragm connection. It could be stator-to-diaphragm or stator-to-stator arcing but I think that's less likely.

Arcing at the bias supply connection would sound like it's coming from the entire panel rather than the local connection area because it affects the charge across the entire diaphragm.

Some ML's just have a wire taped in place against the diaphragm (piss poor if you ask me) and some use a copper foil strip contacting the diaphragm (much better).

If you have the wire-only contact; you could apply some conductive paint of the kind used to repair automobile rear window de-icing grids (available at auto parts stores), or you could solder a copper foil strip to the wire to make a larger contact patch to the diaphragm.

Hope this helps

Is this the red wire going to the Mylar?
How do I know what type of connection I have?

 

[Jazzman53]

The red wire has to be the bias wire because it enters between the stators. The problem is accessing the contact area.

BTW; I build DIY ESLs (not a ML owner) and I'm not that familiar with how the panels are bonded. I believe all ML models use double-sided adhesive tape to bond the panels and to bond the horizontal spars to the rear stator. The spars may or may not be bonded to the front stator as well (there would be no need to do that, and it would make servicing the panel easier.

Accessing the diaphragm connection will require removing the front stator. I don't know if the front stator can be removed without damaging the diaphragm, so that is the question.

Perhaps someone else on this forum has disassembled a ML panel and will respond.

 

[Shaftish]

The red wire has to be the bias wire because it enters between the stators. The problem is accessing the contact area.

BTW; I build DIY ESLs (not a ML owner) and I'm not that familiar with how the panels are bonded. I believe all ML models use double-sided adhesive tape to bond the panels and to bond the horizontal spars to the rear stator. The spars may or may not be bonded to the front stator as well (there would be no need to do that, and it would make servicing the panel easier.

Accessing the diaphragm connection will require removing the front stator. I don't know if the front stator can be removed without damaging the diaphragm, so that is the question.

Perhaps someone else on this forum has disassembled a ML panel and will respond.

Bad luck haha, naturally it is the wire that I can´t get to haha.
Yes, they have used double sided adhesive. After I have written with the ESL rebuild company in Australia I figured that there is a very high risk separating the panel, over 50% chans of failure. But as it is right now it can´t be used anyhow so I guess that the risk factor is out the door.

If I pull the red cable it seems to be in place, no wiggle. If I manage to separate the panel, how do I make the wire stick? If we assume that this is the problem.

 

[Jazzman53]

Bad luck haha, naturally it is the wire that I can´t get to haha.
Yes, they have used double sided adhesive. After I have written with the ESL rebuild company in Australia I figured that there is a very high risk separating the panel, over 50% chans of failure. But as it is right now it can´t be used anyhow so I guess that the risk factor is out the door.

If I pull the red cable it seems to be in place, no wiggle. If I manage to separate the panel, how do I make the wire stick? If we assume that this is the problem.

I was hoping someone else on this forum with experience refurbishing ML panels would jump in and save the day.

The panel is arcing somewhere, probably from a corroded diaphragm connection, and if the front stator is bonded on, I can't imagine getting it off and leaving the diaphragm intact. If not; the fix will require replacing the diaphragm.

If you're handy and willing to attempt replacing the diaphragm yourself; you might try contacting ER Audio in Australia-- they make diaphragm replacement kits for ESLs and they may have a kit for your specific panel, with instructions and everything needed.

 

[Shaftish]

What does arcing mean?

 

[Shaftish]

I have been in contact with them. Quite a big job, building a rig and all. I'm not sure how good it will actually be, is it possible to get the correct tension and precision?

 

[Jazzman53]

What does arcing mean?

An "arc" is an electrical spark", and it typically makes a "pop" sound. And I believe the rapid pops I hear in the video of your panel playing is arcing.

Before you take the panel apart, it's a good idea to connect it to the power supply and play it in the dark. In a darkened room, the arcing would be visible.

If the arcing is at the diaphragm/bias wire connection, it would be obscured by the solid edge portion of the stator and not visible. Whereas, any arcing within the perforated portion of the stators, or along their edges would be visible in the dark.

Not seeing any visible arcing would provide some confidence that the arcing is at the bias supply connection and nowhere else.

If you see any arcing within the perforated areas or along the stator edges, then mark the location for repair. Repetitive arcing (except at the bias supply wire connection) would indicate a burn thru of the stator's insulation coating (powder coat). If you do find a burn thru, you could repair it by locally overcoating the burn thru with enamel paint or a dab of RTV silicone. This is important because you don't want to spend all that effort replacing the diaphragm only to discover you had a burn thru elsewhere and the panel still arcs.